Terminal apparatus and base station apparatus

ABSTRACT

First information indicating a length of a cyclic prefix for an inter-terminal apparatus signal transmitted to the other terminal apparatus and second information indicating a length of a cyclic prefix for an uplink signal in the EUTRAN, from a base station apparatus of the EUTRAN are received from a base station apparatus of the EUTRAN.

TECHNICAL FIELD

The present invention relates to a terminal apparatus and a base stationapparatus.

This application is based upon and claims the benefit of priority fromthe Japanese Patent Application No. 2013-163099, filed on Aug. 6, 2013,the entire content of which is incorporated herein by reference.

BACKGROUND ART

Evolved Universal Terrestrial Radio Access (EUTRA) and Evolved UniversalTerrestrial Radio Access Network (EUTRAN) for cellular mobilecommunication have been studied in the 3rd Generation PartnershipProject (3GPP). The EUTRA and the EUTRAN are called Long term Evolution(LTE). In the LTE, a base station apparatus is called evolved NodeB(eNodeB), and a terminal apparatus is called User Equipment (UE). TheLTE is a cellular communication system in which an area covered by thebase station apparatus is arranged cellularly at multiple locations. Asingle base station apparatus may manage multiple cells.

In the 3GPP, Proximity Services (ProSe) are studied. The ProSe includesProSe discovery and ProSe communication. The ProSe discovery is aprocess which uses the EUTRA so as to specify that one terminalapparatus is in proximity to the other terminal apparatus. The ProSecommunication is communication between two terminal apparatuses inproximity to each other, which uses a EUTRAN communication pathestablished between two terminal apparatuses. For example, thecommunication path may be directly established between the terminalapparatuses.

The ProSe discovery and the ProSe communication are respectively calledD2D discovery and D2D communication. The D2D discovery and the D2Dcommunication are collectively called D2D.

NPL 1 describes that a subset of resource blocks is reserved for theD2D, that a network configures a set of D2D resources, and that aterminal apparatus is permitted to transmit a D2D signal in theconfigured resource.

CITATION LIST Non Patent Literature

NPL 1: “D2D for LTE Proximity Services: Overview”, R1-132028, 3 GPPTSG-RAN WG1 Meeting #73, May 20 to 24, 2013

SUMMARY OF INVENTION Technical Problem

However, in a case where the D2D is performed within LTE coverage,interference occurs between cellular communication in the related artand the D2D. A case has not been sufficiently studied where the terminalapparatus performs the D2D and the cellular communicationsimultaneously. An aspect of the present invention is made in view ofthe above-described problem, and aims to provide a terminal apparatuswhich can efficiently perform the D2D and a base station apparatus whichcontrols the terminal apparatus.

Solution to Problem

(1) According to a first aspect of the present invention, a terminalapparatus that communicates with an Evolved Universal Terrestrial RadioNetwork (EUTRAN) includes a reception unit which receives firstinformation indicating a length of a cyclic prefix for an inter-terminalapparatus signal transmitted to the other terminal apparatus and secondinformation indicating a length of a cyclic prefix for an uplink signalin the EUTRAN, from a base station apparatus of the EUTRAN.

(2) In the first aspect of the present invention, the inter-terminalapparatus signal may include a signal related to discovery betweenterminal apparatuses and a signal related to communication between theterminal apparatuses, and the first information may individuallyindicate the length of the cyclic prefix for the signal related to thediscovery between the terminal apparatuses and the length of the cyclicprefix for the signal related to the communication between the terminalapparatuses.

(3) In the first aspect of the present invention, the reception unit mayreceive, from the base station apparatus of the EUTRAN, the firstinformation for each of multiple sets of resources for theinter-terminal apparatus signal.

(4) In the first aspect of the present invention, the terminal apparatusmay further include a transmission unit which notifies the otherterminal apparatus of the length of the cyclic prefix for theinter-terminal apparatus signal.

(5) In the first aspect of the present invention, the resources for theinter-terminal apparatus signal may be resources of an uplink componentcarrier of a cell in a frequency division duplex system in the EUTRAN,or resources of uplink subframes in a time division duplex system in theEUTRAN.

(6) In the first aspect of the present invention, the reception unit maydetect the length of the cyclic prefix of a downlink signal, based onthe downlink signal in the EUTRAN.

(7) According to a second aspect of the present invention, a basestation apparatus on an Evolved Universal Terrestrial Radio Network(EUTRAN) which communicates with a terminal apparatus includes atransmission unit which transmits first information indicating a lengthof a cyclic prefix for an inter-terminal apparatus signal transmitted tothe other terminal apparatus and second information indicating a lengthof a cyclic prefix for an uplink signal in the EUTRAN, to the terminalapparatus.

(8) In the second aspect of the present invention, the inter-terminalapparatus signal may include a signal related to discovery betweenterminal apparatuses and a signal related to communication between theterminal apparatuses, and the first information may individuallyindicate the length of the cyclic prefix for the signal related to thediscovery between the terminal apparatuses and the length of the cyclicprefix for the signal related to the communication between the terminalapparatuses.

(9) In the second aspect of the present invention, the transmission unitmay transmit the first information on each of multiple sets of resourcesfor the inter-terminal apparatus signal to the terminal apparatus.

(10) In the second aspect of the present invention, the terminalapparatus may notify the other terminal apparatus of the length of thecyclic prefix for the inter-terminal apparatus signal.

(11) In the second aspect of the present invention, the resources forthe inter-terminal apparatus signal may be resources of an uplinkcomponent carrier of a cell in a frequency division duplex system in theEUTRAN, or resources of uplink subframes in a time division duplexsystem in the EUTRAN.

Advantageous Effects of Invention

According to an aspect of the invention, a terminal apparatus canefficiently perform D2D, and a base station apparatus can control theterminal apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram of a radio communication system accordingto the present embodiment.

FIG. 2 is a diagram illustrating a schematic configuration of a radioframe according to the present embodiment.

FIG. 3 is a diagram illustrating a configuration of a slot according tothe present embodiment.

FIG. 4 is a diagram illustrating D2D resources according to the presentembodiment.

FIG. 5 is a diagram illustrating transmission timing of a terminalapparatus 1 according to the present embodiment.

FIG. 6 is a diagram illustrating information related to D2D transmittedin a cellular link according to the present embodiment.

FIG. 7 is a schematic block diagram illustrating a configuration of theterminal apparatus 1 according to the present embodiment.

FIG. 8 is a schematic block diagram illustrating a configuration of abase station apparatus 3 according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment according to the present invention will bedescribed.

In the present embodiment, a terminal apparatus is configured with oneor multiple cells. A technology which allows the terminal apparatus tocommunicate via the multiple cells is called cell aggregation or carrieraggregation. The present invention may be applied to each of themultiple cells configured for the terminal apparatus. In addition, thepresent invention may be applied to a part of the multiple configuredcells. The cell configured for the terminal apparatus is called aserving cell.

Multiple configured serving cells include one primary cell and one ormultiple secondary cells. The primary cell is a serving cell in which aninitial connection establishment procedure is performed, a serving cellin which a connection re-establishment procedure is initiated, or a cellwhich is indicated as the primary cell in a handover procedure. Thesecondary cell may be configured when or after Radio Resource Control(RRC) connection is established.

In the case of the cell aggregation, a Time Division Duplex (TDD) systemor a Frequency Division Duplex (FDD) system may be applied to all of themultiple cells. A cell to which the TDD system is applied and a cell towhich the FDD system is applied may be aggregated.

FIG. 1 is a conceptual diagram of a radio communication system accordingto the present embodiment. In FIG. 1, the radio communication systemincludes terminal apparatuses 1A to 1C, a repeater 2, and a base stationapparatus 3. The terminal apparatuses 1A to 1C are collectively referredto as a terminal apparatus 1. The repeater 2 has a function ofamplifying a signal received from the terminal apparatus 1 andtransmitting the amplified signal. A serving cell 4 is an area coveredby the base station apparatus 3 (LTE).

An uplink 5 is a link from the terminal apparatus 1 to the base stationapparatus 3. In the uplink 5, a signal may be transmitted from theterminal apparatus 1 to the base station apparatus 3 without involvingthe repeater. A downlink 7 is a link from the base station apparatus 3to the terminal apparatus 1. In addition, the uplink 5 and the downlink7 are called a cellular link or cellular communication path. Inaddition, communication between the terminal apparatus 1 and the basestation apparatus 3 is called cellular communication.

A D2D link 9 is a link between the terminal apparatuses 1. The D2D link9 is called a D2D communication path, a ProSe link, or a ProSecommunication path. In the D2D link 9, D2D discovery and D2Dcommunication are performed. The D2D discovery is a process/procedurewhich specifies that the terminal apparatus 1 is in proximity to theother terminal apparatus 1 by using the EUTRA. The D2D communication iscommunication between two terminal apparatuses 1 in proximity to eachother, which uses a EUTRAN communication path established between thetwo terminal apparatuses 1. For example, the communication path may bedirectly established between the terminal apparatuses 1.

The D2D link 9 may include a ProSe-assisted Wireless Local Area Network(WLAN) direct communication path. For example, the two terminalapparatuses 1 in proximity to each other may be discovered based on theD2D discovery, and the EUTRAN provides the two terminal apparatuses 1with configuration information of the WLAN. The two terminal apparatuses1 may establish the ProSe-assisted Wireless Local Area Network (WLAN)direct communication path based on the configuration information of theWLAN. For example, the two terminal apparatuses 1 in proximity to eachother may be discovered based on the D2D discovery using the EUTRAN, andthe EUTRAN communication path or the ProSe-assisted Wireless Local AreaNetwork (WLAN) direct communication path is established between the twodiscovered terminal apparatuses 1.

A physical channel and a physical signal according to the presentembodiment will be described.

A downlink physical channel and a downlink physical signal arecollectively called a downlink signal. An uplink physical channel and anuplink physical signal are collectively called an uplink signal. Thephysical channel is used for transmitting information output from ahigher layer. The physical signal is not used for transmitting theinformation output from the higher layer, but is used by a physicallayer.

In FIG. 1, the following uplink physical channels are used for uplinkradio communication.

-   -   Physical Uplink Control Channel (PUCCH)    -   Physical Uplink Shared Channel (PUCCH)    -   Physical Random Access Channel (PRACH)

The PUCCH is a physical channel used for transmitting Uplink ControlInformation (UCI). The Uplink Control Information includes Channel StateInformation (CSI) of the downlink, a Scheduling Request (SR) indicatinga request for a PUSCH resource, and acknowledgement(ACK)/negative-acknowledgement (NACK) for downlink data (Transportblock, Downlink-Shared Channel: DL-SCH). The ACK/NACK is called HARQ-ACKor HARQ feedback.

The PUSCH is a physical channel used for transmitting uplink data(Uplink-Shared Channel: UL-SCH) and/or the HARQ-ACK and/or channel stateinformation.

The PRACH is a physical channel used for transmitting a random accesspreamble. The PRACH is used in an initial connection establishmentprocedure, a handover procedure, or a connection re-establishmentprocedure.

In FIG. 1, the following uplink physical signal is used in uplink radiocommunication.

-   -   Uplink Reference Signal (ULRS)

In the present embodiment, the following two types of the uplinkreference signal are used.

-   -   Demodulation Reference Signal (DMRS)    -   Sounding Reference Signal (SRS)

The DMRS relates to transmission of the PUSCH or the PUCCH. The DMRS issubjected to time multiplexing with the PUSCH or the PUCCH. The basestation apparatus 3 uses the DMRS in order to perform channelcompensation of the PUSCH or the PUCCH. Transmitting the PUSCH and theDMRS together is simply called transmitting the PUSCH. Transmitting thePUCCH and the DMRS together is simply called transmitting the PUCCH. TheSRS does not relate to the transmission of the PUSCH or the PUCCH. Thebase station apparatus 3 uses the SRS in order to measure an uplinkchannel state.

In FIG. 1, the following downlink physical channels are used in thedownlink radio communication.

-   -   Physical Broadcast Channel (PBCH)    -   Physical Control Format Indicator Channel (PCFICH)    -   Physical Hybrid automatic repeat request Indicator Channel        (PHICH)    -   Physical Downlink Control Channel (PDCCH)    -   Enhanced Physical Downlink Control Channel (EPDCCH)    -   Physical Downlink Shared Channel (PDSCH)    -   Physical Multicast Channel (PMCH)

The PBCH is used for broadcasting a Master Information Block (MIB,Broadcast Channel: BCH) commonly used in the terminal apparatus 1. TheMIB is transmitted at an interval of 40 ms, and the MIB is repeatedlytransmitted at a cycle of 10 ms. For example, the MIB includesinformation indicating an SFN (system frame number). The SFN is a radioframe number. The MIB is system information.

The PCFICH is used for transmitting information indicating a region(OFDM symbol) to be used in transmitting the PDCCH.

The PHICH is used for transmitting a HARQ indicator (HARQ feedback)indicating Acknowledgement (ACK) or Negative Acknowledgement (NACK) forthe uplink data (Uplink Shared Channel: UL-SCH) received by the basestation apparatus 3.

The PDCCH and the EPDCCH are used for transmitting Downlink ControlInformation (DCI). The Downlink Control Information is called a DCIformat. The Downlink Control Information includes a downlink grant andan uplink grant. The downlink grant is called downlink assignment ordownlink allocation.

The uplink grant is used for scheduling of a single PUSCH within asingle cell. The uplink grant is used for scheduling of a single PUSCHwithin a certain subframe. The downlink grant is used for scheduling ofa single PDSCH within a single cell. The downlink grant is used forscheduling of the PDSCH within the same subframe as the subframe fromwhich the downlink is transmitted.

A Cyclic Redundancy Check (CRC) parity bit is added to the DCI format.The CRC parity bit is scrambled by a Cell-Radio Network TemporaryIdentifier (C-RNTI) or a Semi Persistent Scheduling Cell-Radio NetworkTemporary Identifier (SPS C-RNTI). The C-RNTI and the SPS C-RNTI areidentifiers for identifying the terminal apparatus 1 within a cell. TheC-RNTI is used for controlling a resource of the PDSCH or a resource ofthe PUSCH in a single subframe. The SPS C-RNTI is used for allocatingthe resource of the PDSCH or the PUSCH cyclically.

The PDSCH is used for transmitting downlink data (Downlink SharedChannel: DL-SCH).

The PMCH is used for transmitting multicast data (Multicast Channel:MCH).

In FIG. 1, the following downlink physical signals are used in thedownlink radio communication.

-   -   Synchronization Signal (SS)    -   Downlink Reference Signal (DL RS)

The synchronization signal is used by the terminal apparatus 1 forsynchronizing a downlink frequency domain and a time domain. In the FDDsystem, the synchronization signal is arranged in a subframe 0 and asubframe 5 within a radio frame.

The downlink reference signal is used by the terminal apparatus 1 forperforming channel compensation of a downlink physical channel. Thedownlink reference signal is used by the terminal apparatus 1 forcalculating downlink channel state information. The downlink referencesignal is used by the terminal apparatus 1 for measuring geographiclocations of the terminal apparatus 1.

In the present embodiment, the following five types of the downlinkreference signal are used.

-   -   Cell-specific Reference Signal (CRS)    -   URS (UE-specific Reference Signal) related to PDSCH    -   DMRS (Demodulation Reference Signal) related to EPDCCH    -   Non-Zero Power Channel State Information-Reference Signal (NZP        CSI-RS)    -   Zero Power Channel State Information-Reference Signal (ZP        CSI-RS)    -   Multimedia Broadcast and Multicast Service over a Single        Frequency Network Reference signal (MBSFN RS)

The CRS is transmitted to all bands of a subframe. The CRS is used fordemodulating PBCH/PDCCH/PHICH/PCFICH/PDSCH. The CRS may be used by theterminal apparatus 1 for calculating the downlink channel stateinformation. The PBCH/PDCCH/PHICH/PCFICH are each transmitted by anantenna port used in transmitting the CRS.

The URS related to the PDSCH is transmitted through a subframe and aband which are used in transmitting the PDSCH to which the URS isrelated. The URS is used for demodulating the PDSCH to which the URS isrelated. The PDSCH is transmitted by the antenna port used intransmitting the CRS or an antenna port used in transmitting the URS.

The DMRS related to the EPDCCH is transmitted through a subframe and aband which are used in transmitting the EPDCCH to which the DMRS isrelated. The DMRS is used for demodulating the EPDCCH to which the DMRSis related. The EPDCCH is transmitted by an antenna port used intransmitting the DMRS.

The NZP CSI-RS is transmitted through a configured subframe. The basestation apparatus 3 configures a resource to which the NZP CSI-RS istransmitted. The NZP CSI-RS is used by the terminal apparatus 1 forcalculating the downlink channel state information. The terminalapparatus 1 performs signal measurement (channel measurement) using theNZP CSI-RS.

The base station apparatus 3 configures a resource of the ZP CSI-RS. Thebase station apparatus 3 transmits the ZP CSI-RS with a zero power. Thatis, the base station apparatus 3 does not transmit the ZP CSI-RS. Thebase station apparatus 3 does not transmit the PDSCH and the EPDCCH inthe resource configured to include the ZP CSI-RS. For example, theterminal apparatus 1 can measure interference in a resource to which theNZP CSI-RS corresponds in a certain cell.

The MBSFN RS is transmitted through all bands of a subframe used intransmitting the PMCH. The MBSFN RS is used for demodulating the PMCH.The PMCH is transmitted by an antenna port used in transmitting theMBSFN RS.

In FIG. 1, in radio communication of D2D link 9 between the terminalapparatuses 1, a downlink signal, an uplink signal, or a signal newlydefined for the D2D (physical channel and physical signal) may be used.A signal (physical channel and physical signal) transmitted and receivedin the D2D link 9 is called a signal used for the D2D, a signal for theD2D, and a D2D signal.

The BCH, MCH, UL-SCH, and DL-SCH are transport channels. A channel usedin a Medium Access Control (MAC) layer is called the transport channel.A unit of data in the transport channel used in the MAC layer is calleda transport block (TB) or a MAC Protocol Data Unit (PDU). A HybridAutomatic Repeat Request (HARQ) is controlled for each transport blockin the MAC layer. The transport block is a unit of data delivered to aphysical layer by the MAC layer. In the physical layer, the transportblock is mapped into a code word, and encoding processing is performedfor each code word.

The structure of a radio frame according to the present embodiment willbe described.

In the LTE, two radio frame structures are supported. The two radioframe structures are a frame structure type 1 and a frame structure type2. The frame structure type 1 can be applied to the FDD. The framestructure type 2 can be applied to the TDD.

FIG. 2 is a diagram illustrating a schematic configuration of the radioframe according to the present embodiment. In FIG. 2, the horizontalaxis is a time axis. In addition, the radio frames of the type 1 and thetype 2 respectively have lengths of 10 ms, and are defined by 10subframes. The subframes respectively have lengths of 1 ms each, and aredefined by two contiguous slots. The slots respectively have lengths of0.5 ms each. The-i^(th) subframe within the radio frame consists of the(2×i)^(th) slot and the (2×i+1)^(th) slot.

The following three types of subframes are defined for the framestructure type 2.

-   -   Downlink Subframe    -   Uplink Subframe    -   Special Subframe

The downlink subframe is a subframe reserved for the downlinktransmission. The uplink subframe is a subframe reserved for the uplinktransmission. The special subframe consists of three fields. The threefields are a Downlink Pilot Time Slot (DwPTS), a Guard Period (GP), andan Uplink Pilot Time Slot (UpPTS). The total length of the DwPTS, theGP, and the UpPTS is 1 ms. The DwPTS is a field reserved for thedownlink transmission. The UpPTS is a field reserved for the uplinktransmission. The GP is a field in which the downlink transmission andthe uplink transmission are not performed. The special subframe mayconsists only of the DwPTS and the GP, or may consists only of the GPand the UpPTS.

The radio frame of the frame structure type 2 consists of at least thedownlink subframe, the uplink subframe, and the special subframe.

The configuration of the slot according to the present embodiment willbe described.

FIG. 3 is a diagram illustrating the configuration of the slot accordingto the present embodiment. In FIG. 3, a normal Cyclic Prefix (CP) isapplied to the OFDM symbol or the SC-FDMA symbol. A physical signal or aphysical channel transmitted in each slot is expressed by a resourcegrid. In FIG. 3, the horizontal axis is a time axis, and a vertical axisis a frequency axis. In the downlink, the resource grid is defined bymultiple subcarriers and multiple OFDM symbols. In the uplink, theresource grid is defined by multiple subcarriers and multiple SC-FDMAsymbols. For example, in the D2D link, the resource grid may be definedby the multiple subcarriers and the multiple SC-FDMA symbols. The numberof subcarriers configuring one slot depends on the bandwidth of a cell.The number of the OFDM symbols or the SC-FDMA symbols which configureone slot is seven. Each element within the resource grid is called aresource element. The resource element is identified using the number ofthe subcarriers and the number of the OFDM symbols or the SC-FDMAsymbols.

The resource block is used for expressing mapping of a certain physicalchannel (PDSCH or PUSCH) into the resource element. In the resourceblock, a virtual resource block and a physical resource block aredefined. The certain physical channel is first mapped into the virtualresource block. Thereafter, the virtual resource block is mapped intothe physical resource block. One physical resource block is defined byseven contiguous OFDM symbols in a time domain or the SC-FDMA symbolsand twelve contiguous subcarriers in a frequency domain. Consequently,one physical resource block is configured to include the resourceelements (the number is 7×12). In addition, one physical resource blockcorresponds to one slot in the time domain, and corresponds to 180 kHzin the frequency domain. The physical resource block is numbered fromzero in the frequency domain.

An extended CP may be applied to the OFDM symbols or the SC-FDMAsymbols. In the case of the extended CP, the number of the OFDM symbolsor the SC-FDMA symbols configuring one slot is seven.

Arrangement of the physical channel and the physical signal according tothe present embodiment will be described.

FIG. 4 is a diagram illustrating D2D resources according to the presentembodiment. In FIG. 4, the horizontal axis is a time axis, and thevertical axis is a frequency axis. In FIG. 4, D represents the downlinksubframe, S represents the special subframe, and U represents the uplinksubframe. One FDD cell corresponds to one downlink carrier, or onedownlink carrier and one uplink carrier. One TDD cell corresponds to oneTDD carrier. One D2D cell corresponds to one D2D carrier.

In the FDD cell, the downlink signal used for cellular communication isarranged in the subframe of the downlink carrier, the uplink signal usedfor the cellular communication is arranged in the subframe of the uplinkcarrier, and the D2D signal used for the D2D is arranged in the subframeof the uplink carrier. The carrier corresponding to the cell in thedownlink is called a downlink component carrier. In addition, thecarrier corresponding to the cell in the uplink is called an uplinkcomponent carrier.

In the TDD cell, the downlink signal used for the cellular communicationis arranged in the downlink subframe and the DwPTS, the uplink signalused for the cellular communication is arranged in the uplink subframeand the UpPTS, and the D2D signal used for the D2D is arranged in theuplink subframe and the UpPTS.

The D2D cell is a dedicated cell for the D2D, and the D2D signal usedfor the D2D is arranged in the D2D cell. That is, The D2D carrier towhich the D2D cell corresponds is a dedicated carrier for the D2D. TheD2D carrier is called a D2D dedicated spectrum or Public Safety (PS)spectrum. The D2D resource in the D2D cell is called the D2D resource ofthe D2D dedicated spectrum or a PS resource. In the 3GPP, it has beenstudied when the D2D dedicated spectrum is used for the PS. The PSresource may also be used for another purpose except for as the PS. TheD2D cell used for the PS may not be a serving cell.

Without establishing a cellular link, the terminal apparatus 1 mayestablish the D2D link for the PS in the D2D dedicated spectrum. In acase where the terminal apparatus 1 establishes the D2D link for the PSin the D2D dedicated spectrum without establishing the cellular link,the terminal apparatus 1 may establish the cellular link in advance, mayperform a configuration related to the D2D for the PS, and may getauthorization on the D2D for the PS.

The base station apparatus 3 controls the D2D resources reserved for theD2D. The base station apparatus 3 reserves a part of the resources ofthe uplink carrier of the FDD cell as the D2D resources. The basestation apparatus 3 reserves a part of the resources of the uplinksubframe and the UpPTS of the TDD cell as the D2D resources. The basestation apparatus 3 reserves all or a part of the resources of the D2Dcell as the D2D resources.

The base station apparatus 3 transmits a higher layer signal includinginformation indicating the D2D resources reserved in each cell to theterminal apparatus 1. The terminal apparatus 1 sets a parameterD2D-ResourceConfig indicating the D2D resources reserved in each cell,based on the higher layer signal received from the base stationapparatus 3. That is, the base station apparatus 3 sets the parameterD2D-ResourceConfig indicating the D2D resources reserved in each cell tothe terminal apparatus 1 via the higher layer signal.

A part of the frequency band of the uplink carrier corresponding to theFDD cell may be reserved as the D2D dedicated spectrum. In addition, apart of the frequency band of the uplink subframe corresponding to theTDD cell may be reserved as the D2D dedicated spectrum.

The base station apparatus 3 may notify the terminal apparatus 1 ofwhether or not each set of the D2D resources is the PS resource. Theterminal apparatus 1 does not simultaneously perform transmissionprocessing of the D2D and reception processing of the D2D in onecarrier.

It is preferable that the D2D discovery/communication in the D2Dresources used for another purpose except for the PS be controlled ormonitored by the base station apparatus 3.

A configuration method of CP length according to the present embodimentwill be described.

Preferably, the CP length is controlled so that delay time of a delaywave falls within the CP length. The base station apparatus 3 controlsthe CP length of the uplink and the downlink. The base station apparatus3 may individually control the CP length of the uplink and the downlinkfor each serving cell.

Based on the PBCH for the serving cell, the terminal apparatus 1 detectsthe CP length of the downlink signal for the serving cell, excludes thePMCH and the MBSFN RS. The extended CP is always applied to the PMCH andthe MBSFN RS.

The base station apparatus 3 transmits the higher layer signal includinginformation indicating the CP length of the uplink signal in the servingcell to the terminal apparatus 1. The terminal apparatus 1 sets aparameter UL-CyclicPrefixLength indicating the CP length of the uplinkin the serving cell, based on the higher layer signal received from thebase station apparatus 3. That is, the base station apparatus 3 sets theparameter UL-CyclicPrefixLength indicating the CP length of the uplinkin the serving cell to the terminal apparatus 1 via the higher layersignal. For example, as illustrated in FIG. 1, in a case where therepeater 2 is used in the uplink, the extended CP may be applied in theuplink in view of a processing delay in the repeater 2.

A D2D communication path from a certain terminal apparatus 1 to anotherterminal apparatus 1 is the same as a D2D communication path fromanother terminal apparatus 1 to the certain terminal apparatus 1.Therefore, in the D2D, it is preferable that the CP length used fortransmission from a certain terminal apparatus 1 to another terminalapparatus 1 be the same as the CP length used for transmission fromanother terminal apparatus 1 to the certain terminal apparatus 1.

Since the D2D is communication between the terminal apparatuses 1 inproximity to each other, it is expected that the delay time of the delaywave will be short. Therefore, the CP length in the D2D link may be thenormal CP. That is, the CP length in the D2D link may be defined byspecifications in advance and may be fixed.

However, a synchronization method in the D2D has not been sufficientlystudied, thereby causing a possibility that the synchronization betweenthe terminal apparatuses 1 may be inaccurate. Therefore, the CP lengthin the D2D link may be that of the extended CP.

In addition, based on the synchronization method for the D2D, a radiocondition between the terminal apparatuses 1, a geographical distancebetween the terminal apparatuses 1, and/or the uplink signaltransmission timing for cellular communication in each terminalapparatus 1, the terminal apparatus 1 or the base station apparatus 3may control the CP length in the D2D link. That is, the CP length forthe D2D, the CP length for the downlink, and the CP length for theuplink may be controlled individually. That is, the CP length for eachof the D2D signal and the Uplink signal which are transmitted throughthe same carrier may be configured individually.

For example, the base station apparatus 3 may transmit, to the terminalapparatus 1, the higher layer signal including the informationindicating the CP length for the D2D. The terminal apparatus 1 may set aparameter D2D-CyclicPrefixLength indicating the CP length for the D2D,based on the higher layer signal received from the base stationapparatus 3. That is, the base station apparatus 3 may set the parameterD2D-CyclicPrefixLength indicating the CP length for the D2D to theterminal apparatus 1 via the higher layer signal.

Based on the D2D signal and/or information received from the otherterminal apparatus 1, the terminal apparatus 1 may determine the CPlength for the D2D. The terminal apparatus 1 may transmit theinformation indicating the CP length for the D2D to the other terminalapparatus 1. The other terminal apparatus 1 may determine the CP lengthfor the D2D, based on the information indicating the CP length for theD2D and received from the terminal apparatus 1.

The CP length of the D2D signal for the D2D discovery may be differentfrom the CP length for the D2D communication. The base station apparatus3 may transmit the higher layer signal including information indicatingthe CP length for the D2D discovery to the terminal apparatus 1. Thebase station apparatus 3 may transmit the higher layer signal includinginformation indicating the CP length for the D2D communication to theterminal apparatus 1.

The CP length for the D2D discovery and/or the D2D communication may bezero.

Transmission timing for the uplink according to the present embodimentwill be described.

A Timing Advance Group (TAG) is a group of serving cells configured byan RRC layer. The same timing reference cell and the same Timing Advance(TA) value are used for the serving cells included in the same TAG andwith the configured uplink.

A Primary Timing Advance Group (PTAG) is the TAG including a primarycell. A timing reference cell for the PTAG is the primary cell.

A secondary Timing Advance Group (STAG) is the TAG which does notinclude the primary cell. The STAG includes at least one serving cellwith the configured uplink. The timing reference cell for the STAG isany one secondary cell included in the STAG.

The D2D cell may not belong to any TAG.

The base station apparatus 3 transmits a Timing Advance (TA) command forPTAG and a TA command for the STAG to the terminal apparatus 1. The TAcommand is transmitted together with a TAG identity (ID) specifying theTAG to which the TA command corresponds. The TAG ID for the PTAG iszero. The TAG ID for the STAG is configured by the base stationapparatus 3 and is any number from one to three.

In a case where the TA command for the PTAG is received, the terminalapparatus 1 adjusts uplink transmission timing for the PUSCH/PUCCH/SRSof the primary cell, based on the received TA command. In a case wherethe secondary cell belongs to the PTAG, the uplink transmission timingfor the PUSCH/PUCCH/SRS of the secondary cell is the same as the uplinktransmission timing for the primary cell.

In a case where the TA command for the STAG is received, the terminalapparatus 1 adjusts the uplink transmission timing for thePUSCH/PUCCH/SRS of all the secondary cells within the STAG, based on thereceived TA command. The uplink transmission timing for thePUSCH/PUCCH/SRS is the same for all of the secondary cells within theSTAG.

The terminal apparatus 1 measures reference timing based on the downlinksignal (for example, synchronization signal) of the timing referencecell. The terminal apparatus 1 determines a value of the TA for theUplink transmission, based on the TA command. The terminal apparatus 1determines the uplink transmission timing, based on the measuredreference timing and the value of the TA.

Transmission timing for the D2D according to the present embodiment willbe described.

FIG. 5 is a diagram illustrating the transmission timing of the terminalapparatus 1 according to the present embodiment. In FIG. 5, thehorizontal axis is a time axis. In FIG. 5, downlink transmission timingis transmission timing of the downlink signal transmitted by the basestation apparatus 3, downlink reception timing is reception timing ofthe downlink signal received by the terminal apparatus 1, and uplinktransmission timing is transmission timing of the uplink signaltransmitted by the terminal apparatus 1. The uplink reception timing isreception timing of the uplink signal received by the base stationapparatus 3. The D2D transmission timing is transmission timing of theD2D signal transmitted by the terminal apparatus 1. It is preferablethat the base station apparatus 3 control the value of the TA for theuplink transmission so that the downlink transmission timing and theuplink transmission timing coincide with each other.

In a case where the resource for the uplink transmission and the D2Dresource are subjected to time multiplexing and the uplink transmissiontiming and the D2D transmission timing are different from each other,the D2D signal in a certain subframe interferes with the uplink signalin the adjacent subframe, on the base station apparatus 3 side.Consequently, it is preferable that the D2D transmission timing be thesame as the uplink transmission timing on the terminal apparatus 1 side.In this manner, the D2D signal transmitted through a subframe #4 in FIG.5 interferes with only the subframe #4 on the base station apparatus 3side, and thus does not interfere with the adjacent subframes #3 and #5.

The D2D transmission timing of the terminal apparatus 1 in the D2Ddedicated spectrum may be different from the uplink transmission timing.For example, the D2D transmission timing in the D2D dedicated spectrummay be determined, based on a Global Navigation Satellite System (GNSS)and/or the D2D signal received from another terminal apparatus 1.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the same cell, the uplink transmission timing and the D2Dtransmission timing are the same as each other, and the CP length of theuplink signal and the CP length of the D2D signal are the same as eachother, the terminal apparatus 1 may simultaneously transmit the uplinksignal and the D2D signal on the same subframe (timing) of the samecell.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the same cell, and the uplink transmission timing and the D2Dtransmission timing are different from each other, the terminalapparatus 1 may drop either the transmission of the uplink signal or thetransmission of the D2D signal.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the same cell, and the CP length of the uplink signal and theCP length of the D2D signal are different from each other, the terminalapparatus 1 may drop either the transmission of the uplink signal or thetransmission of the D2D signal.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the same cell, the terminal apparatus 1 may drop either thetransmission of the uplink signal or the transmission of the D2D signal.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the same cell, the terminal apparatus 1 may simultaneouslytransmit the uplink signal and the D2D signal through the same subframe(timing) of the same cell.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the different cell, the terminal apparatus 1 maysimultaneously transmit the uplink signal and the D2D signal through thesame subframe (timing) of the different cell.

In a case where the transmission of the uplink signal and thetransmission of the D2D signal occur in the same subframe (timing,symbol) of the different cell, the terminal apparatus 1 may drop eitherthe transmission of the uplink signal or the transmission of the D2Dsignal.

A TA timer according to the present embodiment will be described.

The terminal apparatus 1 manages the TA timer for each TAG. Whenreceiving the TA command, the terminal apparatus 1 starts or restartsthe TA timer related to the TAG to which the TA command is applied.

In a case where the TA timer related to the PTAG expires, for theuplink, the terminal apparatus 1 performs the following processing (fromA1 to A3).

-   -   Processing (A1): For all of the serving cells, a HARQ buffer        related to transmission processing of the uplink is flushed.    -   Processing (A2): For all of the serving cells, the PUCCH/SRS        related to the uplink is released.    -   Processing (A3): it is considered that all of the running TA        timers expire.

In a case where the TA timer related to the STAG expires, the terminalapparatus 1 performs the following processing (B1 and B2) for theuplink.

-   -   Processing (B1): For all the serving cells belonging to the        STAG, all the HARQ buffers related to the transmission        processing of the uplink are flushed.    -   Processing (B2): For all of the serving cells belonging to the        STAG, the PUCCH/SRS related to the uplink is released.

In a case where the TA timer related to the TAG to which the servingcell belongs is not running, the terminal apparatus 1 does not performthe uplink transmission through the serving cell except for randomaccess preamble transmission. In a case where the TA timer related tothe PTAG is not running, the terminal apparatus 1 does not perform theuplink transmission through all the serving cells except for the randomaccess preamble transmission through the primary cell.

Furthermore, in a case where the TA timer related to the PTAG expires,the terminal apparatus 1 performs part of or all of the followingprocessing (C1 to C8) for all of the cells configured with D2D resource,except for the cells in the D2D dedicated spectrum. In addition, in acase where the TA timer related to the STAG expires, the terminalapparatus 1 performs part or all of the following processing (C1 to C8)for all of the cells belonging the STAG, except for the cells in the D2Ddedicated spectrum.

-   -   Processing (C1): The procedure for the D2D discovery is stopped.    -   Processing (C2): The D2D communication is stopped.    -   Processing (C3): ProSe-assisted WLAN direct communication is        stopped/disconnected.    -   Processing (C4): The D2D resource is released.    -   Processing (C5): All of the HARQ buffers related to transmission        processing of the D2D are flushed.    -   Processing (C6): All soft buffers related to reception        processing of the D2D are flushed.    -   Processing (C7): The D2D is deactivated.    -   Processing (C8): All configurations for the D2D are discarded.

In the processing (C3), WLAN communication except for the ProSe-assistedWLAN direct communication may not be stopped/disconnected.

In the processing (C8), the MAC layer may instruct the RRC layer so asto discard all of the configurations for the D2D in the RRC layer.

In a case where the TA timer related to the TAG to which the servingcell belongs is not running, the terminal apparatus 1 does not performthe D2D transmission through the serving cell except for the D2Dtransmission through the D2D dedicated spectrum. In a case where the TAtimer related to the PTAG is not running, the terminal apparatus 1 doesnot perform the D2D transmission through all of the serving cells exceptfor the D2D transmission through the D2D dedicated spectrum.

In a case where the D2D is performed between the terminal apparatuses 1which have different values of the TA in the uplink transmission, due tothe fact that the D2D transmission timing and the uplink transmissiontiming have to be the same, the D2D transmission timing in one terminalapparatus 1 and the D2D transmission timing in another terminalapparatus 1 become different from each other.

Therefore, the terminal apparatus 1 may transmit information indicatinga timing reference cell in the terminal apparatus 1 and informationindicating the D2D transmission timing (value of the TA which isobtained from the reference timing measured, based on the downlinksignal of the timing reference cell) in the terminal apparatus 1, to theother terminal apparatus 1.

In addition, the D2D transmission timing may be controlled between theterminal apparatuses 1. The terminal apparatus 1 may determine the valueof the TA for the D2D, based on the D2D signal received from the otherterminal apparatus 1 and transmit the TA command indicating the value ofthe TA to the other terminal apparatus 1.

In this case, the TA timer for the D2D may be defined. In a case wherethe terminal apparatus 1 receives the TA command for the D2D, theterminal apparatus 1 may start or restart the TA timer. In a case wherethe TA timer for the D2D expires, the terminal apparatus 1 may performpart or all of the processing (C1 to C8) for the D2D resource to whichthe TA timer corresponds.

Activation and deactivation of the D2D according to the presentembodiment will be described.

A function of the D2D is activated or deactivated by the terminalapparatus 1. It is preferable that the activation and deactivation ofthe D2D be controlled by the MAC layer. For example, in the terminalapparatus 1, the D2D may be activated or deactivated by a user or by aninput from an application.

For example, the terminal apparatus 1 may activate or deactivate the D2Dbased on the D2D command (information) received from the base stationapparatus 3. The D2D command is used for activating and deactivating theD2D. The D2D command may include an MAC Control Element (CE) or an RRCmessage. In addition, the D2D command may include anactivation/deactivation MAC CE. The activation/deactivation MAC CE isused by the base station apparatus 3 for activating and deactivating thesecondary cell.

For example, in a case where a D2D deactivation timer expires, the D2Dmay be deactivated by the terminal apparatus 1. In a case where the D2Dis activated based on the input from the user or the application, theterminal apparatus 1 may start or restart a D2D deactivation timer. In acase where the D2D is activated based on the received D2D command, theterminal apparatus 1 may start or restart the D2D deactivation timer.

The base station apparatus 3 may set the duration of the D2Ddeactivation timer in the terminal apparatus 1 via the higher layersignal. The duration of the D2D deactivation timer may vary for eachcell. In addition, the duration of the D2D deactivation timer may varyfor each set of the D2D resource. In addition, the duration of the D2Ddeactivation timer may vary for each D2D communication path.

The D2D deactivation timer may not be defined for the D2D dedicatedspectrum. In addition, the duration of the D2D deactivation timer forthe D2D dedicated spectrum may be fixed (for example, infinitely). Thatis, the base station apparatus 3 may transmit the higher layer signalincluding information indicating the duration of the D2D deactivationtimer for the cell or the set of the D2D resource except for the D2Ddedicated spectrum, to the terminal apparatus 1.

In a case where the function of the D2D is activated, the terminalapparatus 1 may transmit information indicating that the function of theD2D is activated to the base station apparatus 3. The informationindicating that the function of the D2D is activated may be included inthe MAC CE or the RRC message.

In a case where the function of the D2D is activated based on the D2Dcommand, the terminal apparatus 1 may not report the informationindicating that the function of the D2D is activated, to the basestation apparatus 3. The terminal apparatus 1 may transmit/report theACK (HARQ-ACK) for a transport block including the D2D command to thebase station apparatus 3 through the PUSCH or the PUCCH.

In a case where the function of the D2D is deactivated, the terminalapparatus 1 may transmit information indicating that the function of theD2D is deactivated, to the base station apparatus 3. The informationindicating that the function of the D2D is deactivated may be includedin the MAC CE or the RRC message.

In a case where the function of the D2D is deactivated based on the D2Dcommand, the terminal apparatus 1 may not report the informationindicating that the function of the D2D is deactivated, to the basestation apparatus 3. The terminal apparatus 1 may transmit/report theACK (HARQ-ACK) for the transport block including the D2D command, to thebase station apparatus 3 through the PUSCH or the PUCCH. In a case wherethe function of the D2D is deactivated, the terminal apparatus 1 mayperform part or all of the processing (C1 to C6).

In a case where the function of the D2D is deactivated, the terminalapparatus 1 may transmit the information indicating that the function ofthe D2D is deactivated, to the other terminal apparatus 1 which performsthe D2D communication. A function of the D2D discovery and a function ofthe D2D communication may be individually activated or deactivated.

In a case where the function of the D2D is activated, the terminalapparatus 1

-   -   (D1): may perform and start the D2D discovery, in the D2D link;    -   (D2): may perform and start the D2D communication, in the D2D        link;    -   (D3): may perform and start the ProSe-assisted WLAN direct        communication, in the D2D link;    -   (D4): may perform reception processing and monitoring of the        downlink signal related to the D2D link, in the downlink;    -   (D5): may perform transmission processing on the uplink signal        related to the D2D link, in the uplink.

In a case where the function of the D2D is deactivated, the terminalapparatus 1

-   -   (E1): does not perform and start the D2D discovery, in the D2D        link;    -   (E2): does not perform and start the D2D communication, in the        D2D link;    -   (E3): does not perform and start the ProSe-assisted WLAN direct        communication, in the D2D link;    -   (E4): does not perform the reception processing and monitoring        of the downlink signal related to the D2D link, in the downlink;    -   (E5): does not perform the transmission processing on the uplink        signal related to the D2D link, in the uplink.

For example, the downlink signal related to the D2D link includesinformation/DCI used for controlling transmission power for transmissionof the D2D signal, information/DCI instructing the start of a procedureof D2D discovery, information/DCI indicating a format of the D2D signalrelated to the D2D discovery, information/DCI used for generating asequence of the D2D signal related to the D2D discovery, information/DCIindicating the D2D resource for the D2D discovery or the D2Dcommunication, information related to the configuration ofProSe-assisted WLAN direct communication, and information indicating theconfiguration of the D2D link.

For example, the uplink signal related to the D2D link includesinformation related to the D2D link. The information related to the D2Dlink will be described in detail later.

This enables the EUTRAN and the user to activate and deactivate thefunction of the D2D at any desired timing. The function of the D2D maybe activated and deactivated for each cell, for each application, or foreach D2D communication path. In addition, one D2D deactivation timer maybe defined for each cell, for each application, or for each D2Dcommunication path.

The information/DCI instructing the start of a procedure of D2Ddiscovery, the information/DCI used for generating a sequence of the D2Dsignal related to the D2D discovery, the information/DCI indicating theD2D resource for the D2D discovery may be transmitted together via asingle PDCCH or a single EPDCCH.

The terminal apparatus 1 receiving the three distinct information/DCIitems may perform the following processing (F1 to F4).

-   -   Processing (F1): The procedure of the D2D discovery is started        based on the information/DCI instructing to start the procedure        of the D2D discovery.    -   Processing (F2): A sequence of the D2D signal related to the D2D        discovery is generated based on the information/DCI used for        generating a sequence of the D2D signal related to D2D        discovery.    -   Processing (F3): The D2D resource used for transmitting the D2D        signal related to the D2D discovery is selected based on the        information /DCI indicating the D2D resource for the D2D        discovery.    -   Processing (F4): the D2D signal of a generated sequence is        transmitted in the selected D2D resource.

FIG. 6 is a diagram illustrating the information related to the D2Dwhich is transmitted in the cellular link according to the presentembodiment. In FIG. 6, a cellular communication path is establishedbetween the base station apparatus 3 and the terminal apparatus 1A. InFIG. 6, a D2D communication path is established between the terminalapparatus 1A and the terminal apparatus 1B.

The base station apparatus 3 and the terminal apparatus 1A performtransmission and reception processing of the information related to theD2D so that the base station apparatus 3 controls and/or monitors theD2D communication path and/or the ProSe-assisted WLAN directcommunication path.

The terminal apparatus 1A transmits the information related to the D2Dcapability to the base station apparatus 3 (S600). Based on the receivedinformation related to the D2D capability, the base station apparatus 3transmits information indicating a configuration of the D2D link to theterminal apparatus 1A (S602). Based on the received informationindicating the configuration of the D2D link, the terminal apparatus 1Aestablishes D2D connection (S604). The terminal apparatus 1A transmitsinformation related to the established D2D link (connection) to the basestation apparatus 3 (S606).

In S604, the terminal apparatus 1A may transmit/transfer the informationrelated to the configuration of the D2D link to the terminal apparatus1B.

In FIG. 6, the terminal apparatus 1B may establish a cellularcommunication path connected to the other base station apparatus 3. Theterminal apparatus 1B may transmit the information related to the D2Dlink to the other base station apparatus 3. Multiple base stationapparatuses 3 may transmit-receive/transfer the information related tothe D2D link via backhaul established between the base stationapparatuses 3.

In FIG. 6, the terminal apparatus 1B may establish a cellularcommunication path connected to the base station apparatus 3. Theterminal apparatus 1B may transmit the information related to the D2Dlink to the base station apparatus 3.

In FIG. 6, only a part of the terminal apparatuses 1 (for example, oneterminal apparatus 1) within a group of the terminal apparatuses 1performing the D2D may transmit the information related to the D2D linkto the EUTRAN (base station apparatus 3). The part of the terminalapparatuses 1 may be determined from between the terminal apparatuses 1performing the D2D. In addition, the part of the terminal apparatuses 1may be designated by the base station apparatus 3. In addition, the basestation apparatus 3 may configure whether to report the informationrelated to the D2D link via the higher layer signal for each of theterminal apparatuses 1.

This can avoid a case where the same information related to the D2D linkis repeatedly transmitted to the EUTRAN using the uplink resource.Accordingly, it is possible to improve a usage efficiency of the uplinkresource.

The information related to the D2D capability may include part or all ofdistinct information items (G1 to G17). The distinct information items(G1 to G17) may be respectively transmitted at different timings.

-   -   Information (G1): Information indicating whether or not the        terminal apparatus 1 supports a capability of the ProSe-assisted        WLAN direct communication    -   Information (G2): Information indicating a standard of the WLAN        supported by the terminal apparatus 1 (for example, Institute of        Electrical and Electronics Engineers (IEEE) 802.11a/b/g/n/ac,        IEEE802.11 series)    -   Information (G3): Information indicates the standard of the WLAN        supported by the terminal apparatus 1 and which can be used for        the ProSe-assisted WLAN direct communication    -   Information (G4): Information indicating whether or not the        terminal apparatus 1 supports a capability of the D2D discovery        in the EUTRAN    -   Information (G5): Information indicating whether or not the        terminal apparatus 1 supports a capability of the D2D        communication in the EUTRAN    -   Information (G6): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the D2D discovery/communication in the EUTRAN and the        ProSe-assisted WLAN direct communication    -   Information (G7): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the cellular communication and the ProSe-assisted        WLAN direct communication    -   Information (G8): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the cellular communication and the D2D        discovery/communication in a single cell    -   Information (G9): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the transmission on the cellular communication and        the transmission on the D2D discovery/communication in a single        cell    -   Information (G10): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the reception on the cellular communication and the        transmission on the D2D discovery/communication in a single FDD        cell    -   Information (G11): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the reception on the cellular communication and the        reception on the D2D discovery/communication in a single FDD        cell    -   Information (G12): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the cellular communication in a certain cell and the        D2D discovery/communication in another cell    -   Information (G13): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the transmission on the cellular communication in a        certain cell and the transmission on the D2D        discovery/communication in another cell    -   Information (G14): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the reception on the cellular communication in a        certain cell and the reception on the D2D        discovery/communication in another cell    -   Information (G15): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the transmission on the cellular communication in a        certain cell and the reception on the D2D        discovery/communication in another cell    -   Information (G16): Information indicating whether or not the        terminal apparatus 1 supports a capability of simultaneously        performing the reception on the cellular communication in a        certain cell and the transmission on the D2D        discovery/communication in another cell    -   Information (G17): Information requesting to        schedule/allocate/configure of the D2D resources used by the        terminal apparatus 1 for the D2D communication and/or the D2D        discovery

The base station apparatus 3 may transmit information indicating theconfiguration of the D2D link for each set of the D2D resources, to theterminal apparatus 1. Multiple sets of the D2D resources may be arrangedfor one terminal apparatus 1. One set of the D2D resources may beincluded in one cell. Multiple sets of the D2D resources may be arrangedin one cell. One set of the D2D resources may be arranged for each D2Dcommunication path. Multiple D2D communication paths may be establishedin one terminal apparatus 1.

The information indicating the configuration of the D2D link may includepart or all of distinct information items (H1 to H15). The distinctinformation items (H1 to H15) may be respectively transmitted atdifferent timings.

-   -   Information (H1): Information indicating a cell including the        D2D resource    -   Information (H2): Information indicating a subframe including        the D2D resource    -   Information (H3): Information indicating a frequency bandwidth        and/or a frequency position of the D2D resource within a        subframe    -   Information (H4): Information indicating a virtual resource        block or a physical resource block which configures the D2D        resource within a subframe    -   Information (H5): Information indicating a cell including the PS        resource    -   Information (H6): Information indicating a subframe including        the PS resource    -   Information (H7): Information indicating a frequency bandwidth        and/or a frequency position of the PS resource within a subframe    -   Information (H8): Information indicating a virtual resource        block or a physical resource block which configures the PS        resource within a subframe    -   Information (H9): Information indicating validity/instruction of        resource hopping of the D2D signal (for example, the PUSCH)    -   Information (H10): Information indicating a resource hopping        mode of the D2D signal    -   Information (H11): Information indicating validity/instruction        of hopping of the D2D resource    -   Information (H12): Information indicating a hopping mode of the        D2D resource    -   Information (H13): Information indicating a configuration of the        D2D signal related to the D2D discovery    -   Information (H14): Information indicating a configuration of the        D2D signal related to the D2D communication    -   Information (H15): Information indicating a configuration of the        ProSe-assisted WLAN direct communication

The information (H2) may indicate a cycle and an offset with respect tonumbers of subframes for the reserved D2D resource. The information (H2)may be expressed by a bitmap. Each bit of the bitmap may correspond toone subframe.

The hopping mode of the D2D signal includes an inter-subframe mode, andan intra and inter-subframe mode. In the inter-subframe mode, theresources of the D2D signal are hopping in each subframe. In the intraand inter-subframe mode, the resources of the D2D signal are hopping ineach slot.

The information related to the D2D link may include part or all ofdistinct information items (I1 to I42). The distinct information items(I1 to I42) may be respectively transmitted at different timings.

-   -   Information (I1): Information indicating a subset of the D2D        resources used for the D2D discovery and/or the D2D        communication    -   Information (I2): Information indicating a subset of the D2D        resources in which the transmission processing of the D2D signal        is performed    -   Information (I3): Information indicating a subset of the D2D        resources in which the reception processing/monitoring of the        D2D signal is performed    -   Information (I4): Information indicating a band(s) used for the        D2D discovery and/or the D2D communication    -   Information (I5): Information indicating a band(s) in which the        transmission processing of the D2D signal is performed    -   Information (I6): Information indicating a band(s) in which the        reception processing/monitoring of the D2D signal is performed    -   Information (I7): Information indicating a cell(s) used for the        D2D discovery and/or the D2D communication    -   Information (I8): Information indicating a cell(s) in which the        transmission processing of the D2D signal is performed    -   Information (I9): Information indicating a cell(s) in which the        reception processing/monitoring of the D2D signal is performed    -   Information (I10): Information indicating a subframe(s) used for        the D2D discovery and/or the D2D communication    -   Information (I11): Information indicating a subframe(s) in which        the transmission processing of the D2D signal is performed    -   Information (I12): Information indicating a subframe(s) in which        the reception processing/monitoring of the D2D signal is        performed    -   Information (I13): Information indicating the CP length of the        D2D signal    -   Information (I14): Information indicating whether or not the D2D        is performed in the D2D dedicated spectrum    -   Information (I15): Information indicating that the D2D is        started in the D2D dedicated spectrum    -   Information (I16): Information indicating that the D2D is        completed in the D2D dedicated spectrum    -   Information (I17): Information indicating whether or not the D2D        for the PS is performed    -   Information (I18): Information indicating that the D2D for the        PS is started    -   Information (I19): Information indicating that the D2D for the        PS is terminated    -   Information (I20): Information indicating whether or not the        WLAN communication is performed    -   Information (I21): Information indicating that the WLAN        communication is started    -   Information (I22): Information indicating that the WLAN        communication is terminated    -   Information (I23): Information indicating the standard of the        WLAN used in the WLAN communication    -   Information (I24): Information indicating whether or not the        ProSe-assisted WLAN direct communication is performed    -   Information (I25): Information indicating that the        ProSe-assisted WLAN direct communication is started    -   Information (I26): Information indicating that the        ProSe-assisted WLAN direct communication is terminated    -   Information (I27): Information indicating the standard of the        WLAN used in the ProSe-assisted WLAN direct communication    -   Information (I28): Information indicating a channel state        (measured interference) in the D2D communication path and/or the        ProSe-assisted WLAN direct communication path    -   Information (I29): Information indicating Quality of Service        (QoS) in the D2D communication path and/or the ProSe-assisted        WLAN direct communication path    -   Information (I30): Information indicating a traffic amount        transmitted and received in the D2D communication path and/or        the ProSe-assisted WLAN direct communication path    -   Information (I31): Information indicating a traffic amount        transmitted in the D2D communication path and/or the        ProSe-assisted WLAN direct communication path    -   Information (I32): Information indicating a traffic amount        received in the D2D communication path and/or the ProSe-assisted        WLAN direct communication path    -   Information (I33): Information indicating an amount of traffic        (data and packet) in a transmission waiting state in the D2D        communication path and/or the ProSe-assisted WLAN direct        communication path (Buffer Status Report: BSR)    -   Information (I34): Information indicating a communication range        in the D2D communication path and/or the ProSe-assisted WLAN        direct communication path    -   Information (I35): Information indicating priority of a packet        in the D2D communication path and/or the ProSe-assisted WLAN        direct communication path    -   Information (I36): Information indicating an average bit rate in        the D2D communication path and/or the ProSe-assisted WLAN direct        communication path    -   Information (I37): Information indicating average packet delay        in the D2D communication path and/or the ProSe-assisted WLAN        direct communication path    -   Information (I38): Information indicating an average packet loss        rate (Block Error Rate: BLER) in the D2D communication path        and/or the ProSe-assisted WLAN direct communication path    -   Information (I39): Information indicating whether or not the QoS        in the D2D communication path and/or the ProSe-assisted WLAN        direct communication path satisfies the QoS to which a QoS Class        Identifier (QCI) for the D2D communication path and/or the        ProSe-assisted WLAN direct communication channel corresponds    -   Information (I40): Information indicating an identifier        (identity) of the terminal apparatus 1 performing the D2D        communication and/or the ProSe-assisted WLAN direct        communication    -   Information (I41): Information indicating a Public Land Mobile        Network (PLMN)/operator to which the terminal apparatus 1        performing the D2D communication and/or the ProSe-assisted WLAN        direct communication is connected    -   Information (I42): Information indicating a geographic location        of the terminal apparatus 1

The terminal apparatus 1 may transmit the information related to the D2Dlink for each set of the D2D resources, for each D2D communication path,for each ProSe-assisted WLAN direct communication path, and/or for eachapplication, to the base station apparatus 3.

The report on the information related to the D2D link may be triggeredin a case where any state of the distinct information items (I1 to I42)is changed. In addition, the report on the information related to theD2D link may be triggered in a case where any value of the distinctinformation items (I1 to I42) is changed to reach a threshold value orgreater. In addition, the report on the information related to the D2Dlink may be triggered in a case where any value of the distinctinformation items (I1 to I42) when the information related to the D2Dlink is finally reported is different from a current value by thethreshold value or greater. In this case, among the distinct informationitems (I1 to I42), only the distinct information item corresponding tothe trigger may be reported. The report on the information related tothe D2D link may be triggered based on the instruction from the basestation apparatus 3.

For example, in a case where the traffic amount transmitted in the D2Dtransmission path goes beyond the threshold value, the report on theinformation related to the D2D link may be triggered. For example, thereport on the information related to the D2D link may be triggered in acase where the QoS in the D2D communication path and/or theProSe-assisted WLAN direct communication path does not satisfy the QoSto which the QoS Class Identifier (QCI) for the D2D communication pathand/or the ProSe-assisted WLAN direct communication path corresponds.

The terminal apparatus 1 may report the information related to the D2Dlink by using the PUSCH in a case where at least one report on theinformation related to the D2D link is triggered, the PUSCH for initialtransmission in the uplink is allocated, and the information related tothe D2D link can be accommodated in the PUSCH as a result of a logicalchannel prioritization procedure.

The QCI is defined by priority of the packet, a packet delay budget, apacket error loss rate, presence or absence of a guaranteed bit rate.The QCI is a scalar used for comparing specific packet transmissionoperations. The base station apparatus 3 may transmit informationindicating the QCI corresponding to the D2D communication path to theterminal apparatus 1.

The geographic location of the terminal apparatus 1 may be measuredbased on a PRS and/or the Global Navigation Satellite System (GNSS).

For example, the terminal apparatus 1 may determine the subset of theD2D resources used for transmission and reception of the D2D signal fromamong the D2D resources indicated by the information indicating theconfiguration of the D2D link, and may transmit the distinct information(I1) indicating the determined subset of the D2D resources to the basestation apparatus 3.

Hereinafter, a configuration of the apparatuses according to the presentinvention will be described.

FIG. 7 is a schematic block diagram illustrating the configuration ofthe terminal apparatus 1 according to the present embodiment. Asillustrated, the terminal apparatus 1 is configured to include a higherlayer processing unit 101, a control unit 103, a reception unit 105, atransmission unit 107, and a transmit-receive antenna unit 109. Inaddition, the higher layer processing unit 101 is configured to includea radio resource control unit 1011, a scheduling informationinterpretation unit 1013, and a D2D control unit 1015. In addition, thereception unit 105 is configured to include a decoding unit 1051, ademodulation unit 1053, a demultiplexing unit 1055, a radio receptionunit 1057, and a channel measurement unit 1059. In addition, thetransmission unit 107 is configured to include an encoding unit 1071, amodulation unit 1073, a multiplexing unit 1075, a radio transmissionunit 1077, and an uplink reference signal generation unit 1079.

The higher layer processing unit 101 outputs uplink data (transportblock) generated by an operation of a user to the transmission unit 107.In addition, the higher layer processing unit 101 performs processingfor a Medium Access Control (MAC) layer, a Packet Data ConvergenceProtocol (PDCP) layer, a radio Link Control (RLC) layer, and a RadioResource Control (RRC) layer.

The radio resource control unit 1011 included in the higher layerprocessing unit 101 manages various configuration informationitems/parameters of the terminal apparatus 1. The radio resource controlunit 1011 sets the various configuration information items/parameters,based on the higher layer signal received from the base stationapparatus 3. That is, the radio resource control unit 1011 sets thevarious configuration information items/parameters, based on theinformation indicating the various configuration informationitems/parameters received from the base station apparatus 3. Inaddition, the radio resource control unit 1011 generates informationwhich is to be arranged in each uplink channel, and outputs theinformation to the transmission unit 107.

The scheduling information interpretation unit 1013 included in thehigher layer processing unit 101 interprets a DCI format (schedulinginformation) received via the reception unit 105. Based on aninterpretation result of the DCI format, the scheduling informationinterpretation unit 1013 generates control information in order tocontrol the reception unit 105 and the transmission unit 107, andoutputs the control information to the control unit 103.

The D2D control unit 1015 included in the higher layer processing unit101 controls the D2D discovery, the D2D communication, and/or theProSe-assisted WLAN direct communication, based on the variousconfiguration information items/parameters managed by the radio resourcecontrol unit 1011. The D2D control unit 1015 may generate theinformation related to the D2D, which is to be transmitted to the otherterminal apparatus 1 or the EUTRAN (base station apparatus 3).

Based on control information from the higher layer processing unit 101,the control unit 103 generates a control signal for controlling thereception unit 105 and the transmission unit 107. The control unit 103outputs the generated control signal to the reception unit 105 and thetransmission unit 107, and controls the reception unit 105 and thetransmission unit 107.

In accordance with the control signal input from the control unit 103,the reception unit 105 separates, demodulates, and decodes the signalreceived from the base station apparatus 3 via the transmit-receiveantenna unit 109, and outputs decoded information to the higher layerprocessing unit 101.

The radio reception unit 1057 down converts a downlink signal receivedvia the transmit-receive antenna unit 109 into a baseband signal bymeans of quadrature demodulation, removes unnecessary frequencycomponents, and controls an amplification level so that a signal levelis properly maintained. Based on in-phase components and quadraturecomponents of the received signal, the radio reception unit 1057performs the quadrature demodulation, and converts aquadrature-modulated analog signal into a digital signal. The radioreception unit 1057 removes a portion corresponding to a Cyclic Prefix(CP) from the converted digital signal, and performs Fast FourierTransform (FFT) on the CP-removed signal, thereby extracting a signal ina frequency domain.

The demultiplexing unit 1055 separates the extracted signal respectivelyinto the PHICH, the PDCCH, the EPDCCH, the PDSCH, and the downlinkreference signal. In addition, the demultiplexing unit 1055 performscompensation on a channel of the PHICH, the PDCCH, the EPDCCH, and thePDSCH based on an estimation value of the channel which is input fromthe channel measurement unit 1059. In addition, the demultiplexing unit1055 outputs the separated downlink reference signal to the channelmeasurement unit 1059.

The demodulation unit 1053 synthesizes a code corresponding to the PHICHby multiplexing, and performs demodulation using a Binary Phase ShiftKeying (BPSK) modulation scheme on the synthesized signal, therebyoutputting the signal to the decoding unit 1051. The decoding unit 1051decodes the PHICH addressed to the terminal apparatus 1, and outputs adecoded HARQ indicator to the higher layer processing unit 101. Thedemodulation unit 1053 performs the demodulation using a QPSK modulationscheme on the PDCCH and/or EPDCCH, and outputs the signal to thedecoding unit 1051. The decoding unit 1051 attempts to decode the PDCCHand/or EPDCCH. In a case where the decoding is successful, the decodingunit 1051 outputs decoded downlink control information and RNTI to whichthe downlink control information corresponds, to the higher layerprocessing unit 101.

The demodulation unit 1053 performs the demodulation using a modulationscheme notified through downlink grant such as Quadrature Phase ShiftKeying (QPSK), 16 Quadrature Amplitude Modulation (QAM), and 64 QAM, forthe PDSCH, and outputs the signal to the decoding unit 1051. Thedecoding unit 1051 performs decoding based on information related to acoding rate notified through the downlink control information, andoutputs decoded downlink data (transport block) to the higher layerprocessing unit 101.

The channel measurement unit 1059 measures a path loss or a channelstate of the downlink, based on the downlink reference signal input fromthe demultiplexing unit 1055, and outputs the measured path loss or themeasured channel state to the higher layer processing unit 101. Inaddition, the channel measurement unit 1059 calculates an estimationvalue of the downlink channel, based on the downlink reference signal,and outputs the estimation value to the demultiplexing unit 1055. Thechannel measurement unit 1059 performs channel measurement and/orinterference measurement in order to calculate a CQI.

In accordance with the control signal input from the control unit 103,the transmission unit 107 generates the uplink reference signal, encodesand modulates uplink data (transport block) input from the higher layerprocessing unit 101, multiplexes the PUCCH, the PUSCH, and the generateduplink reference signal, and transmits the signal to the base stationapparatus 3 via the transmit-receive antenna unit 109.

The encoding unit 1071 performs encoding such as convolution encodingand block encoding on the uplink control information input from thehigher layer processing unit 101. In addition, the encoding unit 1071performs turbo encoding based on information used in scheduling of thePUSCH.

The modulation unit 1073 modulates an encoded bit input from theencoding unit 1071 using a modulation scheme notified through thedownlink control information such as the BPSK, the QPSK, the 16 QAM, andthe 64 QAM, or using a modulation scheme which is pre-determined foreach channel. The modulation unit 1073 determines the number ofsequences of data to be spatially multiplexed, based on the informationused in scheduling of the PUSCH, and uses Multiple Input Multiple Output(MIMO) Spatial Multiplexing (SM). In this manner, the modulation unit1073 performs mapping of multiple uplink data items transmitted throughthe same PUSCH into multiple sequences, and performs precoding on thesesequences.

The uplink reference signal generation unit 1079 generates a sequenceobtained by a predetermined rule (equation), based on a physical layercell identity (called a PCI or a Cell ID) used for identifying the basestation apparatus 3, a bandwidth for arranging the uplink referencesignal, a cyclic shift notified through the uplink grant, and a value ofparameters for generating a DMRS sequence. In accordance with thecontrol signal input from the control unit 103, the multiplexing unit1075 performs Discrete Fourier Transform (DFT) after rearrangingmodulation symbols of the PUSCH in parallel. In addition, themultiplexing unit 1075 multiplexes signals of the PUCCH and the PUSCHand the generated uplink reference signal for each transmit antennaport. That is, the multiplexing unit 1075 arranges the signals of thePUCCH and the PUSCH and the generated uplink reference signal in aresource element for each transmit antenna port.

The radio transmission unit 1077 performs Inverse Fast Fourier Transform(IFFT) on the multiplexed signal, generates an SC-FDMA symbol, adds a CPto the generated SC-FDMA symbol, generates a digital signal of a baseband, converts the digital signal of the baseband into an analog signal,removes an excessive frequency component using a low pass filter, upconverts the signal into a carrier frequency, amplifies power, andtransmits the signal by outputting the signal to the transmit-receiveantenna unit 109.

FIG. 8 is a schematic block diagram illustrating a configuration of thebase station apparatus 3 according to the present embodiment. Asillustrated, the base station apparatus 3 is configured to include ahigher layer processing unit 301, a control unit 303, a reception unit305, a transmission unit 307, and a transmit-receive antenna unit 309.In addition, the higher layer processing unit 301 is configured toinclude a radio resource control unit 3011, a scheduling unit 3013, anda D2D control unit 3015. In addition, the reception unit 305 isconfigured to include a decoding unit 3051, a demodulation unit 3053, ademultiplexing unit 3055, a radio reception unit 3057, and a channelmeasurement unit 3059. In addition, the transmission unit 307 isconfigured to include an encoding unit 3071, a modulation unit 3073, amultiplexing unit 3075, a radio transmission unit 3077, and a downlinkreference signal generation unit 3079.

The higher layer processing unit 301 performs processing for the MediumAccess Control (MAC) layer, the Packet Data Convergence Protocol (PDCP)layer, the radio Link Control (RLC) layer, and the Radio ResourceControl (RRC) layer. In addition, the higher layer processing unit 301generates control information for controlling the reception unit 305 andthe transmission unit 307, and outputs the control information to thecontrol unit 303.

The radio resource control unit 3011 included in the higher layerprocessing unit 301 generates downlink data which is arranged in thePDSCH of the downlink (transport block), system information, an RRCmessage, and an MAC Control Element (CE), or acquires them from a highernode, and outputs them to the transmission unit 307. In addition, theradio resource control unit 3011 manages various configurationinformation items/parameters of each terminal apparatus 1. The radioresource control unit 1011 may set the various configuration informationitems/parameters for each terminal apparatus 1 via the higher layersignal. That is, the radio resource control unit 1011transmits/broadcasts information indicating the various configurationinformation items/parameters.

The scheduling unit 3013 included in the higher layer processing unit301 determines a frequency and a subframe to which a physical channel(PDSCH and PUSCH) are to be allocated, an encoding rate, a modulationscheme, and transmission power of the physical channel (PDSCH andPUSCH), based on the received channel state information, an estimationvalue of the channel which is input from the channel measurement unit3059, and quality of the channel. The scheduling unit 3013 generatescontrol information (for example, DCI format) in order to control thereception unit 305 and the transmission unit 307, based on a schedulingresult, and outputs the control information to the control unit 303. Thescheduling unit 3013 further determines timings for performingtransmission processing and reception processing.

The D2D control unit 3015 included in the higher layer processing unit301 controls the D2D discovery, the D2D communication, and/or theProSe-assisted WLAN direct communication in the terminal apparatus 1which performs communication using the cellular link, based on thevarious configuration information items/parameters managed by the radioresource control unit 3011. The D2D control unit 3015 may generate theinformation related to the D2D, which is to be transmitted to the otherbase station apparatus 3 or the terminal apparatus 1.

Based on control information from the higher layer processing unit 301,the control unit 303 generates a control signal for controlling thereception unit 305 and the transmission unit 307. The control unit 303outputs the generated control signal to the reception unit 305 and thetransmission unit 307, and controls the reception unit 305 and thetransmission unit 307.

In accordance with the control signal input from the control unit 303,the reception unit 305 separates, demodulates, and decodes the signalreceived from the terminal apparatus 1 via the transmit-receive antennaunit 309, and outputs decoded information to the higher layer processingunit 301. The radio reception unit 3057 down converts an uplink signalreceived via the transmit-receive antenna unit 309 into a basebandsignal by means of quadrature demodulation, removes unnecessaryfrequency components, and controls an amplification level so that asignal level is properly maintained. Based on in-phase components andquadrature components of the received signal, the radio reception unit3057 performs the quadrature demodulation, and converts aquadrature-modulated analog signal into a digital signal.

The radio reception unit 3057 removes a portion corresponding to aCyclic Prefix (CP) from the converted digital signal. The radioreception unit 3057 performs Fast Fourier Transform (FFT) on theCP-removed signal, and extracts a signal in a frequency domain, therebyoutputting the signal to the demultiplexing unit 3055.

The demultiplexing unit 1055 separates the signal input from the radioreception unit 3057 into the PUCCH, the PUSCH, and the uplink referencesignal. This separation is determined in advance by the base stationapparatus 3 using the radio resource control unit 3011, and isperformed, based on allocation information of a radio resource includedin the uplink grant which is notified to each terminal apparatus 1. Inaddition, the demultiplexing unit 3055 performs compensation on achannel of the PUCCH, and the PUSCH, based on an estimation value of thechannel which is input from the channel measurement unit 3059. Inaddition, the demultiplexing unit 3055 outputs the separated uplinkreference signal to the channel measurement unit 3059.

The demodulation unit 3053 performs Inverse Discrete Fourier Transform(IDFT) on the PUSCH, acquires a modulated symbol, and performsdemodulation of the received signal by using a modulation scheme whichis predetermined or which is notified to the terminal apparatus 1 inadvance by the base station apparatus 3 through the uplink grant, suchas the Binary Phase Shift Keying (BPSK), QPSK, 16 QAM, and 64 QAMschemes, for each modulation symbol of the PUCCH and the PUSCH. Based onthe number of sequences which are notified to each terminal apparatus 1in advance through the uplink grant and which are to be spatiallymultiplexed, and information instructing precoding to be performed onthe sequence, the demodulation unit 3053 separates multiple modulationsymbols of the uplink data which is transmitted through the same PUSCHusing the MINO SM.

The decoding unit 3051 performs decoding on an encoded bit of thedemodulated PUCCH and PUSCH by using an encoding rate in a predeterminedencoding scheme which is predetermined or which is notified to theterminal apparatus 1 in advance by the base station apparatus 3 throughthe uplink grant, and outputs the decoded uplink data and uplink controlinformation to the higher layer processing unit 101. In a case where thePUSCH is re-transmitted, the decoding unit 3051 performs decoding usingthe encoded bit held by the HARQ buffer which is to be input from thehigher layer processing unit 301 and the demodulated encoded bit. Thechannel measurement unit 309 measures an estimation value of the channeland quality of the channel, based on the uplink reference signal inputfrom the demultiplexing unit 3055, and outputs both of theses to thedemultiplexing unit 3055 and the higher layer processing unit 301.

In accordance with the control signal input from the control unit 303,the transmission unit 307 generates the downlink reference signal,encodes and modulates the HARQ indicator, the downlink controlinformation, and the downlink data which are input from the higher layerprocessing unit 301, multiplexes the PHICH, the PDCCH, the EPDCCH, thePDSCH, and the downlink reference signal, and transmits the signal tothe terminal apparatus 1 via the transmit-receive antenna unit 309.

The encoding unit 3071 performs encoding on the HARQ indicator, thedownlink control information, and the downlink data which are input fromthe higher layer processing unit 301 by using a predetermined encodingscheme such as the block encoding, the convolution encoding, and theturbo encoding, or performs the encoding by using an encoding schemedetermined by the radio resource control unit 3011. The modulation unit3073 modulates an encoded bit input from the encoding unit 3071 by usinga modulation scheme which is predetermined such as the BPSK, the QPSK,the 16 QAM, and the 64 QAM, or by using a modulation scheme which isdetermined by the radio resource control unit 3011.

The downlink reference signal generation unit 3079 generates a sequenceas the downlink reference signal, which is known to the terminalapparatus 1 and which is obtained by a predetermined rule, based on aphysical layer cell identity (PCI) used for identifying the base stationapparatus 3. The multiplexing unit 3075 multiplexes the modulated symbolof each modulated channel and the generated downlink reference signal.That is, the multiplexing unit 3075 arranges the modulated symbol ofeach modulated channel and the generated downlink reference signal in aresource element.

The radio transmission unit 3077 performs Inverse Fast Fourier Transform(IFFT) on the multiplexed modulated symbol, generates an OFDM symbol,adds a CP to the generated OFDM symbol, generates a digital signal of abase band, converts the digital signal of the base band into an analogsignal, removes an excessive frequency component using a low passfilter, up converts the signal into a carrier frequency, amplifiespower, and transmits the signal by outputting the signal to thetransmit-receive antenna unit 309.

The terminal apparatus 1 according to the present embodiment is theterminal apparatus 1 which communicates with the other terminalapparatus 1 and the base station apparatus 3 (EUTRAN), and includes thereception unit 105 which receives information indicating the length ofthe cyclic prefix for the D2D signal to be transmitted to the otherterminal apparatus 1 and information indicating the length of the cyclicprefix for the uplink signal to be transmitted to the base stationapparatus 3, from the base station apparatus 3.

The terminal apparatus 1 according to the present embodiment includesthe transmission unit 107 which determines whether to transmit both theuplink signal to be transmitted to the base station apparatus 3 and theD2D signal to be transmitted to the other terminal apparatus 1 or anyone of the uplink signal to be transmitted to the base station apparatus3 and the D2D signal to be transmitted to the other terminal apparatus1, based on at least whether or not the transmission timing of theuplink signal to be transmitted to the base station apparatus 3 and thetransmission timing of the D2D signal to be transmitted to the otherterminal apparatus 1 are the same as each other and/or whether or notthe length of the cyclic prefix for the uplink signal to be transmittedto the base station apparatus 3 and the length of the cyclic prefix forthe D2D signal to be transmitted to the other terminal apparatus 1 arethe same as each other, if the uplink signal to be transmitted to thebase station apparatus 3 and the D2D signal to be transmitted to theother terminal apparatus 1 occur simultaneously in the same cell.

The above-described transmission unit 107 may transmit both the uplinksignal to be transmitted to the base station apparatus 3 and the D2Dsignal to be transmitted to the other terminal apparatus 1, if theuplink signal to be transmitted to the base station apparatus 3 and theD2D signal to be transmitted to the other terminal apparatus 1 occurssimultaneously in different cells.

The above-described transmission unit 107 may transmit any one of theuplink signal to be transmitted to the base station apparatus 3 and theD2D signal to be transmitted to the other terminal apparatus 1, if theuplink signal to be transmitted to the base station apparatus 3 and theD2D signal to be transmitted to the other terminal apparatus 1 occurssimultaneously in different cells.

The terminal apparatus 1 according to the present embodiment includesthe D2D control unit 1015 which flushes all the HARQ buffers related tothe transmission processing to the other terminal apparatus 1, in a casewhere the TA timer related to the PTAG expires.

The above-described D2D control unit 1015 flushes all of the softbuffers related to the reception processing from the other terminalapparatus 1, in a case where the TA timer related to the PTAG expires.

The above-described D2D control unit 1015 stops/disconnects thecommunication (D2D communication and ProSe-assisted WLAN directcommunication) with the other terminal apparatus 1, in a case where theTA timer related to the PTAG expires.

The above-described transmission unit 107 does not transmit the D2Dsignal to the other terminal apparatus 1, in a case where the TA timerrelated to the PTAG is not running.

The above-described D2D control unit 1015 flushes all of the HARQbuffers related to the transmission processing to the other terminalapparatus 1 for all the serving cells belonging to the STAG, in a casewhere the TA timer related to the STAG expires.

The above-described D2D control unit 1015 flushes all of the softbuffers related to the reception processing from the other terminalapparatus 1 for all the serving cells belonging to the STAG, in a casewhere the TA timer related to the STAG expires.

The above-described D2D control unit 1015 stops/disconnects thecommunication (D2D communication and ProSe-assisted WLAN directcommunication) with the other terminal apparatus 1 in all the servingcells belonging to the STAG, in a case where the TA timer related to theSTAG expires.

The above-described transmission unit 107 does not transmit the D2Dsignal to the other terminal apparatus 1 in the D2D resource related tothe STAG, in a case where the TA timer related to the STAG is notrunning.

The above-described D2D control unit 1015 activates and deactivates thefunction of the communication between the terminal apparatuses 1 in theMAC layer.

The above-described D2D control unit 1015 activates and deactivates thefunction of the communication between the terminal apparatuses 1, basedon the input by the user or by the application.

The above-described D2D control unit 1015 activates and deactivates thefunction of the communication between the terminal apparatuses 1, basedon the D2D command (information) received from the base stationapparatus 3.

The above-described transmission unit 107 transmits ACK for thetransport block including the D2D command (information) through thePUSCH or the PUCCH to the base station apparatus 3.

The above-described transmission unit 107 transmits the informationindicating that the function of the communication between the terminalapparatuses 1 is activated, to the base station apparatus 3.

The above-described transmission unit 107 transmits the informationindicating that the function of the communication between the terminalapparatuses 1 is deactivated, to the base station apparatus 3.

The above-described D2D control unit 1015 starts or restarts the timerwhen the function of the communication between the terminal apparatuses1 is activated or re-activated, and deactivates the function of thecommunication between the terminal apparatuses 1 in a case where thetimer expires.

The above-described D2D control unit 1015 flushes all of the HARQbuffers related to the transmission processing to the other terminalapparatus 1 in a case where the function of the communication betweenthe terminal apparatuses 1 is deactivated.

The above-described D2D control unit 1015 flushes all of the softbuffers related to the reception processing from the other terminalapparatus 1 in a case where the function of the communication betweenthe terminal apparatuses 1 is deactivated.

The terminal apparatus 1 according to the present embodiment can performand then start communication between the terminal apparatuses 1, in acase where the function of the communication between the terminalapparatuses 1 is activated. In addition, the terminal apparatus 1according to the present embodiment does not perform and then does notstart communication between the terminal apparatuses 1, in a case wherethe function of the communication between the terminal apparatuses 1 isdeactivated.

The above-described reception unit 105 does not perform receptionprocessing and monitoring of the D2D signal from the other terminalapparatus 1, in a case where the function of the communication betweenthe terminal apparatuses 1 is deactivated. The above-described receptionunit 105 may perform reception processing and monitoring of the D2Dsignal from the other terminal apparatus 1, in a case where the functionof the communication between the terminal apparatuses 1 is activated.

The above-described transmission unit 107 does not perform transmissionprocessing of the D2D signal to the other terminal apparatus 1, in acase where the function of the communication between the terminalapparatuses 1 is deactivated. The above-described transmission unit 107may perform transmission processing of the D2D signal to the otherterminal apparatus 1, in a case where the function of the communicationbetween the terminal apparatuses 1 is activated.

The above-described transmission unit 107 transmits the informationrelated to the function of the communication with the other terminalapparatus 1 to the base station apparatus 3. The information related tothe function of the communication with the other terminal apparatus 1includes part or all of the distinct information items (G1 to G17).

The information related to the function of the communication with theother terminal apparatus 1 includes the information indicating standardsof the wireless LAN supported by the terminal apparatus 1.

The information related to the function of the communication with theother terminal apparatus 1 includes the information indicating whetheror not the terminal apparatus 1 supports capability to simultaneouslyperform the communication with the base station apparatus 3 and thewireless LAN direct communication.

The information related to the function of the communication with theother terminal apparatus 1 includes the information indicating whetheror not the terminal apparatus 1 supports capability to simultaneouslyperform the communication with the base station apparatus 3 in a certaincell and the communication with the other terminal apparatus 1 in thecertain cell.

The information related to the function of the communication with theother terminal apparatus 1 includes the information indicating whetheror not the terminal apparatus 1 supports capability to simultaneouslyperform the communication with the base station apparatus 3 in a certaincell and the communication with the other terminal apparatus 1 inanother certain cell.

The above-described transmission unit transmits the information relatedto the communication path with the other terminal apparatus 1, to thebase station apparatus 3. The information related to the communicationpath with the other terminal apparatus 1 partially or entirely includesthe distinct information items (I1 to I42).

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating a resource usedfor communicating with the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating a band used forcommunicating with the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating a cell used forcommunicating with the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating a subframe usedfor communicating with the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating a CP length ofa signal to be transmitted to the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating whether or notthe wireless LAN communication with the other terminal apparatus 1 isperformed.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating an amount oftraffic which is transmitted to the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information indicating an amount oftraffic which is received from the other terminal apparatus 1.

The information related to the communication path with the otherterminal apparatus 1 includes the information related to the QoS in thecommunication path with the other terminal apparatus 1.

The base station apparatus 3 according to the present embodiment is thebase station apparatus 3 that communicates with the terminal apparatus 1which communicates with the other terminal apparatus 1, and includes thetransmission unit 307 that transmits the information indicating thelength of the cyclic prefix for the signal transmitted to the otherterminal apparatus 1 by the terminal apparatus 1, the informationindicating the length of the cyclic prefix for the signal transmitted tothe base station apparatus 3 by the terminal apparatus 1, theinformation related to the function of the communication with the otherterminal apparatus 1, the information related to the communication pathwith the other terminal apparatus 1, the information instructing toactivate the function of the communication between the terminalapparatuses 1, and the information instructing to deactivate thefunction of the communication between the terminal apparatuses 1, to theterminal apparatus 1.

The base station apparatus 3 according to the present embodimentincludes the reception unit 305 which receives the informationindicating that the function of the communication between the terminalapparatuses 1 is activated and the information indicating that thefunction of the communication between the terminal apparatuses 1 isdeactivated.

The above-described reception unit 305 receives the ACK for thetransport block including the information instructing to activate thefunction of the communication between the terminal apparatuses 1 and theACK including the information instructing to deactivate the function ofthe communication between the terminal apparatuses 1, from the terminalapparatus 1, through the PUSCH or the PUCCH.

In this manner, the D2D can be efficiently performed between theterminal apparatuses 1. In addition, the base station apparatus 3 canefficiently control the D2D between the terminal apparatuses 1 by usingthe cellular link.

A program for operating the base station apparatus 3 and the terminalapparatus 1 according to the present invention may be a program (programwhich causes a computer to execute a process) for controlling a CentralProcessing Unit (CPU) so as to realize functions of the above-describedembodiment according to the present invention. Then, information itemshandled by these apparatuses are temporarily accumulated in a RandomAccess Memory (RAM) during the processing, and then are stored invarious types of Read Only Memory (ROM) such as a Flash ROM or a HardDisk Drive (HDD) so as to be read out, corrected, and written by the CPUwhen necessary.

The terminal apparatus 1 and the base station apparatus 3 may bepartially realized by a computer. In this case, a program for realizinga control function thereof may be recorded in a computer-readablerecording medium. The program recorded in the recording medium may beread out and executed so as to realize the control function.

A “computer system” herein is a computer system incorporated in theterminal apparatus 1 or the base station apparatus 3, and includes an OSor hardware such as peripheral devices. In addition, the“computer-readable recording medium” means a storage device such as aflexible disk, a magneto-optical disk, a portable medium such as the ROMand a CD-ROM, and the hard disk incorporated in the computer system.

Furthermore, the “computer-readable recording medium” represents thosewhich hold a program dynamically in a short time, such as acommunication line in a case where the program is transmitted via anetwork such as the Internet or a communication circuit such as atelephone circuit, and may include those which hold the program for afixed period of time, such as a volatile memory inside the computersystem serving as a server or a client in the above-described case. Inaddition, the above-described program may be those which partiallyrealize the above-described function, and further may be those which canrealize the above-described function in combination with another programalready recorded in the computer system.

In addition, the base station apparatus 3 according to theabove-described embodiment can also be realized as an assembly body(apparatus group) configured to have multiple apparatuses. Eachapparatus configuring the apparatus group may partially or entirelyinclude each function or each functional block of the base stationapparatus 3 according to the above-described embodiment. As theapparatus group, it may be sufficient enough as long as the base stationapparatus 3 is provided with each general function or each generalfunctional block. In addition, the terminal apparatus 1 according to theabove-described embodiment can also communicate with the base stationapparatus serving as the assembly body.

In addition, the base station apparatus 3 according to theabove-described embodiment may be the Evolved Universal TerrestrialRadio Access Network (EUTRAN). In addition, the base station apparatus 3according to the above-described embodiment may partially or entirelyhave the function of the higher node for eNodeB.

In addition, the terminal apparatus 1 and the base station apparatus 3according to the above-described embodiment may be partially or entirelyrealized as an LSI typically serving as an integrated circuit, or as achip set. Each functional block of the terminal apparatus 1 and the basestation apparatus 3 may be individually incorporated in a chip, or maybe partially or entirely integrated into a chip. In addition, a methodof circuit integration is not limited to the LSI, and may be realized bya dedicated circuit or a general-purpose processor. In addition, in acase where an advanced semiconductor technology introduces a newintegrated circuit technology for replacing the LSI, the technologyenables the integrated circuit to be used.

In addition, in the above-described embodiment, the terminal apparatushas been described as an example of the communication apparatus.However, the present invention is not limited thereto. The presentinvention can also be applied to the terminal apparatus or thecommunication apparatus of a stationary type or a non-mobile typeelectronic device which is installed indoors and outdoors, for example,such as AV equipment, kitchen equipment, cleaning-washing machines,air-conditioning equipment, office equipment, vending machines, andother household equipment.

Hitherto, the embodiment of the invention has been described in detailwith reference to the drawings. A specific configuration is not limitedto the embodiment, and includes design modification within a scope notdeparting from the gist of the invention. In addition, the presentinvention can be modified in various ways within the scope disclosed inClaims. An embodiment obtained by appropriately combining technicalmeans disclosed in each different embodiment is also included in thetechnical scope of the present invention. In addition, a configurationof replacing elements providing the same advantageous effect with eachother, which are the elements disclosed in the above-describedrespective embodiments, is also included therein.

APPENDIX 1

There is provided a terminal apparatus that communicates with an EvolvedUniversal Terrestrial Radio Network (EUTRAN). The terminal apparatusincludes a reception unit which receives first information indicating alength of a cyclic prefix for an inter-terminal apparatus signaltransmitted to the other terminal apparatus and second informationindicating a length of a cyclic prefix for an uplink signal in theEUTRAN, from a base station apparatus of the EUTRAN.

APPENDIX 2

In the terminal apparatus disclosed in Appendix 1, the inter-terminalapparatus signal includes a signal related to discovery between terminalapparatuses and a signal related to communication between the terminalapparatuses, and the first information individually indicates the lengthof the cyclic prefix for the signal related to the discovery between theterminal apparatuses and the length of the cyclic prefix for the signalrelated to the communication between the terminal apparatuses.

APPENDIX 3

In the terminal apparatus disclosed in Appendix 1, the reception unitreceives the first information related to each of multiple sets ofresources for the inter-terminal apparatus signal from the base stationapparatus of the EUTRAN.

APPENDIX 4

The terminal apparatus disclosed in Appendix 1 further includes atransmission unit which notifies the other terminal apparatus of thelength of the cyclic prefix for the inter-terminal apparatus signal.

APPENDIX 5

In the terminal apparatus disclosed in Appendix 1, the resources for theinter-terminal apparatus signal are resources of an uplink componentcarrier of a cell in a frequency division duplex system in the EUTRAN,or resources of uplink subframes in a time division duplex system in theEUTRAN.

APPENDIX 6

In the terminal apparatus disclosed in Appendix 1, the reception unitdetects the length of the cyclic prefix of a downlink signal, based onthe downlink signal in the EUTRAN.

APPENDIX 7

There is provided a base station apparatus in an Evolved UniversalTerrestrial Radio Network (EUTRAN) which communicates with a terminalapparatus. The base station apparatus includes a transmission unit whichtransmits first information indicating a length of a cyclic prefix foran inter-terminal apparatus signal transmitted to the other terminalapparatus and second information indicating a length of a cyclic prefixfor an uplink signal in the EUTRAN, to the terminal apparatus.

APPENDIX 8

In the base station apparatus disclosed in Appendix 7, theinter-terminal apparatus signal includes a signal related to discoverybetween the terminal apparatuses and a signal related to communicationbetween the terminal apparatuses, and the first information individuallyindicates the length of the cyclic prefix for the signal related to thediscovery between the terminal apparatuses and the length of the cyclicprefix for the signal related to the communication between the terminalapparatuses.

APPENDIX 9

In the base station apparatus disclosed in Appendix 7, the transmissionunit transmits the first information related to each of multiple sets ofresources for the inter-terminal apparatus signal to the terminalapparatus.

APPENDIX 10

In the base station apparatus disclosed in Appendix 7, the terminalapparatus notifies the other terminal apparatus of the length of thecyclic prefix for the inter-terminal

APPENDIX 11

In the base station apparatus disclosed in Appendix 7, the resources forthe inter-terminal apparatus signal are resources of an uplink componentcarrier of a cell in a frequency division duplex system in the EUTRAN,or resources of an uplink subframe in a time division duplex system inthe EUTRAN.

INDUSTRIAL APPLICABILITY

An aspect of the present invention can be applied to a terminalapparatus which needs to efficiently perform D2D.

REFERENCE SIGNS LIST

1 (1A, 1B, 1C) terminal apparatus

3 base station apparatus

101 higher layer processing unit

103 control unit

105 reception unit

107 transmission unit

109 transmit-receive antenna unit

301 higher layer processing unit

303 control unit

305 reception unit

307 transmission unit

309 transmit-receive antenna unit

1011 radio resource control unit

1013 scheduling information interpretation unit

1015 D2D control unit

3011 radio resource control unit

3013 scheduling unit

3015 D2D control unit

1. A terminal apparatus that communicates with an Evolved UniversalTerrestrial Radio Network (EUTRAN), comprising: a reception unit whichreceives first information indicating a length of a cyclic prefix for aninter-terminal apparatus signal transmitted to the other terminalapparatus and second information indicating a length of a cyclic prefixfor an uplink signal in the EUTRAN, from a base station apparatus of theEUTRAN.
 2. The terminal apparatus according to claim 1, wherein theinter-terminal apparatus signal includes a signal related to discoverybetween terminal apparatuses and a signal related to communicationbetween the terminal apparatuses, and wherein the first informationindividually indicates the length of the cyclic prefix for the signalrelated to the discovery between the terminal apparatuses and the lengthof the cyclic prefix for the signal related to the communication betweenthe terminal apparatuses.
 3. The terminal apparatus according to claim1, wherein the reception unit receives, from the base station apparatusof the EUTRAN, the first information for each of multiple sets ofresources for the inter-terminal apparatus signal.
 4. The terminalapparatus according to claim 1, further comprising: a transmission unitwhich notifies the other terminal apparatus of the length of the cyclicprefix for the inter-terminal apparatus signal.
 5. The terminalapparatus according to claim 1, wherein the resources for theinter-terminal apparatus signal are resources of an uplink componentcarrier of a cell in a frequency division duplex system in the EUTRAN,or resources of uplink subframes in a time division duplex system in theEUTRAN.
 6. The terminal apparatus according to claim 1, wherein thereception unit detects the length of the cyclic prefix of a downlinksignal, based on the downlink signal in the EUTRAN.
 7. A base stationapparatus on an Evolved Universal Terrestrial Radio Network (EUTRAN)which communicates with a terminal apparatus, comprising: a transmissionunit which transmits first information indicating a length of a cyclicprefix for an inter-terminal apparatus signal transmitted to the otherterminal apparatus and second information indicating a length of acyclic prefix for an uplink signal in the EUTRAN, to the terminalapparatus.
 8. The base station apparatus according to claim 7, whereinthe inter-terminal apparatus signal includes a signal related todiscovery between terminal apparatuses and a signal related tocommunication between the terminal apparatuses, and wherein the firstinformation individually indicates the length of the cyclic prefix forthe signal related to the discovery between the terminal apparatuses andthe length of the cyclic prefix for the signal related to thecommunication between the terminal apparatuses.
 9. The base stationapparatus according to claim 7, wherein the transmission unit transmits,to the terminal apparatus, the first information for each of multiplesets of resources for the inter-terminal apparatus signal.
 10. The basestation apparatus according to claim 7, wherein the terminal apparatusnotifies the other terminal apparatus of the length of the cyclic prefixfor the inter-terminal apparatus signal.
 11. The base station apparatusaccording to claim 7, wherein the resources for the inter-terminalapparatus signal are resources of an uplink component carrier of a cellin a frequency division duplex system in the EUTRAN, or resources ofuplink subframes in a time division duplex system in the EUTRAN.